scholarly journals Variability in establishing white clover in pastures on farms

2003 ◽  
pp. 223-228 ◽  
Author(s):  
J.L. Brock ◽  
G.J. Kane
Keyword(s):  
Life Cycle ◽  
Plant Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Grazing Management ◽  
Growth Strategies ◽  
Farmer Knowledge ◽  
Modern Methods ◽  
Direct Drilling ◽  
Seedbed Preparation

Reported problems with inconsistent white clover establishment in pastures prompted a MAF SFF project to investigate the causes. The establishment of white clover in 32 new and renovated paddocks on 16 farms in the Wanganui-Manawatu-Southern Hawke's Bay region was monitored and the inconsistency confirmed in the f irst year. Seedling emergence at 44% (range 22 to 84) for ryegrass and 35% (range 9 to 73) for white clover was low (expected 70%+) and inappropriate grazing management inhibited subsequent plant growth and sward performance to 20% of potential. There were a few good performances, but the 'grass to grass' technique was particularly hard on clover. These problems have arisen as a result of modern methods (e.g. direct drilling and fertiliser N) that are less 'clover friendly', and have moved away from the older proven techniques. Minimal seedbed preparation and method of sowing, combined with lack of knowledge of white clover growth strategies and management requirements are seen as the main causes. Change is inescapable and while modern farming techniques and expectations may have currently placed clover at a disadvantage, the challenge now is how to balance the requirements of the pasture species with the expectations of the farming production system in the future. Keywords: emergence, establishment, farmer knowledge, grazing management, life cycle, sowing conditions, white clover.

Towards improving white clover establishment on farms

2005 ◽  
pp. 35-39
Author(s):  
J.L. Brock ◽  
J. Mckenzie ◽  
S. Pound
Keyword(s):  
White Clover ◽  
Seedling Emergence ◽  
Dairy Farm ◽  
Grazing Management ◽  
N Fixation ◽  
Management Skills ◽  
Sowing Depth ◽  
N Fertility ◽  
Seedbed Preparation

The establishment of new clover-based pastures takes a full year and has two distinct components; seedling emergence from sowing, and subsequent grazing management. A Ministry of Agriculture and Forestry (MAF) Sustainable Farming Fund (SFF) project to investigate the causes of inconsistency of white clover establishment concluded this came primarily from a lack of knowledge of white clover in both sowing and grazing management skills, and reflected how far modern farming technology has moved away from clover-based systems towards nitrogen (N)-boosted systems in recent years. Typically, less than half the seed being sown emerges, for both ryegrass and clover, although good results do occur. A trial looking into seedbed conditions on a dairy farm highlighted the importance of good seedbed consolidation in order to accurately control sowing depth, lifting white clover emergence by 50% and ryegrass by 25% using a roller drill. Consolidation did not affect emergence using a triple disc drill, but it did improve quality of sowing by reducing soil drag and spill by the rear coulters causing excessive burial of the front coulters rows. Differences in emergence were still evident in the performance of the clover in the following summer with 14% clover in the areas that had been hard rolled compared to 4% where it had not. In another trial on a hill soil of lower N fertility status, the taking of hay crops in the first summer, not a normally recommended practise, enhanced clover establishment compared to rotational grazing all year. The roles of clover, N fixation and quality feed, are discussed in the context of how and where clover may fit into modern farm systems. Keywords: emergence, establishment, grazing management, seedbed preparation, sowing methods, white clover

Grazing management of white clover in mixed pastures

2006 ◽  
pp. 303-307 ◽  
Author(s):  
J.L. Brock
Keyword(s):  
Plant Growth ◽  
White Clover ◽  
Management Practices ◽  
Management Strategies ◽  
Dairy Industry ◽  
Poor Performance ◽  
Grazing Management ◽  
Management Systems ◽  
The Face ◽  
Light Management

Poor performance of white clover in the current climate of innovation farm management practices has become problematical, particularly within the dairy industry. There are as many grazing management systems as there are farmers and management guidelines can only be broad generalisations at best, with little interpretive value in the face of the multitude of options available and variables recognised and unrecognised. The principles of plant growth are used to interpret grazing management strategies in order for farmers to have greater understanding of their pastures and determine for themselves what the expectations and outcomes of various management strategies may be. This is of greater relevance to the dairy industry where innovative changes (pasture covers, grass cultivars, pasture renewal and establishment techniques, fertiliser N) can combine to produce a 'clover unfriendly environment'. Keywords: competition, fertiliser N, grazing management, light, management systems, plant growth, protection, space, white clover.

Controlled traffic to increase productivity of irrigated row crops in the semi-arid tropics

1995 ◽  
Vol 35 (4) ◽  
pp. 503 ◽  
Author(s):  
MV Braunack ◽  
JE McPhee ◽  
DJ Reid
Keyword(s):  
Plant Growth ◽  
Soil Properties ◽  
Crop Yield ◽  
Seedling Emergence ◽  
Lateral Spread ◽  
Soil Conditions ◽  
Row Crops ◽  
Seedbed Preparation ◽  
Cone Index ◽  
Controlled Traffic

The tropical environment generally allows 2 crops/year to be grown. Controlled traffic has been suggested as a means of improving soil conditions, which may also lead to increased crop yield. A field trial at Millaroo Research Station, North Queensland, on a cracking clay (Entic Chromustert) studied the effect of controlled traffic (in conjunction with direct drilling and tillage) and conventional ridging on soil properties and crop yield. Maize (Zea mays L. cv. Hybrid 50) was grown as the winter crop and soybean [Glycine max (L.) Merr. cv. Canapolis] as the summer crop. With few exceptions, there was no significant difference between any pair of treatments in sowing line water content, bulk density, aggregate size distribution, seedling emergence, mean time of seedling emergence, and final yield. Differences that did occur between crop cycles were due to climatic variation. Cone index measurements indicated no lateral spread of compaction from the traffic lanes in the controlled traffic system to the soil in the plant growth area. Under the ridged area, however, it appeared that a plough pan began to develop just below the depth of tillage. Although no marked benefit in soil properties or plant yield resulted from controlled traffic, it was possible to grow 2 crops/year for the duration of the experiment. In one season, only the controlled traffic treatments could be planted, due to unsuitable conditions for seedbed preparation. Double cropping under conventional cultivation systems is unreliable, due to the limited opportunity for seedbed preparation at the beginning of the wet season and the large number (up to 8) of operations required to prepare a seedbed. Controlled traffic, restricting soil compaction to the traffic lanes, is a system that helps to maintain a zone more favourable for plant growth, as indicated by the cone index measurements.

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

scholarly journals Effect of different levels of humic acids on the nutrient content, plant growth, and soil properties under conditions of salinity

2011 ◽  
Vol 6 (No. 1) ◽  
pp. 21-29 ◽  
Author(s):  
H. Khaled ◽  
H.A. Fawy
Keyword(s):  
Plant Growth ◽  
Humic Substances ◽  
Humic Acids ◽  
Foliar Application ◽  
N Uptake ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Nutrient Content ◽  
Nutrient Elements ◽  
A Minor

In this study, the effects were investigated of salinity, foliar and soil applications of humic substances on the growth and mineral nutrients uptake of Corn (Hagein, Fardy10), and the comparison was carried out of the soil and foliar applications of humic acid treatments at different NaCl levels. Soil organic contents are one of the most important parts that they directly affect the soil fertility and textures with their complex and heterogenous structures although they occupy a minor percentage of the soil weight. Humic acids are an important soil component that can improve nutrient availability and impact on other important chemical, biological, and physical properties of soils. The effects of foliar and soil applications of humic substances on the plant growth and some nutrient elements uptake of Corn (Hagein, Fardy10) grown at various salt concentrations were examined. Sodium chloride was added to the soil to obtain 20 and 60mM saline conditions. Solid humus was applied to the soil one month before planting and liquid humic acids were sprayed on the leaves twice on 20<sup>th</sup> and 40<sup>th</sup> day after seedling emergence. The application doses of solid humus were 0, 2 and 4 g/kg and those of liquid humic acids were 0, 0.1 and 0.2%. Salinity negatively affected the growth of corn; it also decreased the dry weight and the uptake of nutrient elements except for Na and Mn. Soil application of humus increased the N uptake of corn while foliar application of humic acids increased the uptake of P, K, Mg,Na,Cu and Zn. Although the effect of interaction between salt and soil humus application was found statistically significant, the interaction effect between salt and foliar humic acids treatment was not found significant. Under salt stress, the first doses of both soil and foliar application of humic substances increased the uptake of nutrients.

scholarly journals Impact of Environmental Factors on Seed Germination and Seedling Emergence of White Clover (Trifolium repens L.)

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 190
Author(s):  
Lei Chu ◽  
Yiping Gao ◽  
Lingling Chen ◽  
Patrick E. McCullough ◽  
David Jespersen ◽  
...  
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
White Clover ◽  
Trifolium Repens ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Soil Surface ◽  
High Sensitivity ◽  
Series Of Experiments ◽  
Trifolium Repens L

White clover (Trifolium repens L.) is cultivated as a forage crop and planted in various landscapes for soil conservation. There are numerous reports of failed white clover stands each year. A good understanding of the seed germination biology of white clover in relation to environmental factors is essential to achieve successful stand establishment. A series of experiments were conducted to investigate the impacts of light, temperature, planting depth, drought, and salt stress on seed germination and the emergence of white clover. White clover is negatively photoblastic, and seed germination averaged 63 and 66% under light and complete dark conditions 4 weeks after planting (WAP), respectively. Temperature affected the seed germination speed and rate. At 1 WAP, seeds incubated at 15 to 25 °C demonstrated a significantly higher germination rate than the low temperatures at 5 and 10 °C; however, the germination rate did not differ among the temperature treatments at 4 WAP. The results suggest that white clover germination decreases with increasing sowing depths, and the seeds should be sown on the soil surface or shallowly buried at a depth ≤1 cm to achieve an optimal emergence. White clover seeds exhibited high sensitivity to drought and salinity stress. The osmotic potential and NaCl concentration required to inhibit 50% seed germination were −0.19 MPa and 62.4 mM, respectively. Overall, these findings provide quantifiable explanations for inconsistent establishment observed in field conditions. The results obtained in this research can be used to develop effective planting strategies and support the successful establishment of white clover stands.

Azospirillum–Rhizobium interaction leading to a plant growth stimulation without nodule formation

1985 ◽  
Vol 31 (11) ◽  
pp. 1026-1030 ◽  
Author(s):  
Jacek Plazinski ◽  
Barry G. Rolfe
Keyword(s):  
Plant Growth ◽  
White Clover ◽  
Nitrogen Deficiency ◽  
Growth Stimulation ◽  
Selective Medium ◽  
Acetylene Reduction Activity ◽  
Nodule Formation ◽  
Bacterial Cells ◽  
Indigenous Plasmid ◽  
Plant Growth Stimulation

The effect of inoculation of white clover plants with mixed cultures of Rhizobium trifolii strain ANU870 and Azospirillum brasilense strain SP245 was examined. Ratios of Rhizobium–Azospirillum (R:A) of 1:200 to 1:2500 caused an inhibition of nodulation. However, these nonnodulated plants did not show nitrogen-deficiency symptoms when grown on nitrogenfree medium. When these plants were assayed for acetylene reduction activity a low level of ethylene production was detected. A significant increase in plant dry weights was also observed. Isolation of viable bacterial cells from surface-sterilized root segments of plants inoculated with an R:A ratio of 1:200 revealed that 80% of the bacterial population was made up of the Azospirillum strain. Under laboratory conditions transfer of the Rhizobium Sym(biosis) plasmid pBRIAN to strain SP245 was observed ex planta. However, the Sym plasmid was unstable in Azospirillum. A high frequency of Tn5 transfer from pBRIAN to strain SP245 occurred when strains ANU870 and SP245 were mixed in the rhizosphere and (or) in the root tissue. Tn5 transposed preferentially into the smallest indigenous plasmid of strain SP245 and was easily lost when this strain (SP245::Tn5) was not maintained on selective medium. This mutated Azospirillum strain caused plant growth stimulation when inoculated onto white clover plants.

Vernal Seedling Emergence Model for Common Lambsquarters (Chenopodium album)

Weed Science ◽  
1993 ◽  
Vol 41 (2) ◽  
pp. 309-316 ◽  
Author(s):  
Stephen J. Harvey ◽  
Frank Forcella
Keyword(s):  
Field Data ◽  
Close Agreement ◽  
Chenopodium Album ◽  
Seedling Emergence ◽  
Coefficient Of Determination ◽  
Chemical Methods ◽  
Common Lambsquarters ◽  
Individual Site ◽  
Seedbed Preparation ◽  
Weed Emergence

Knowledge of timing and extent of weed emergence before and immediately after crop seedbed preparation is needed to decrease need for preplant herbicides and increase efficacy of postemergence weed control in crops with either mechanical or chemical methods. Such knowledge is important for weeds that infest most crops over a wide area. For these reasons a mechanistic seedling emergence model based solely on soil temperature was developed for common lambsquarters. The model was validated using four sets of field data collected in 1988, 1990, and 1991 near Morris, MN. Agreement of predicted and observed emergence values across all site-years was 0.95 and the coefficient of determination (R2) was 0.98 (P < 0.001). Agreement for individual site-years was 0.96, 1.08, 1.08, and 0.98 and associated R2values were 0.99, 0.99, 0.99, and 0.98 (P < 0.001 for each site-year), indicating close agreement between predicted and actual emergence values.

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